Lens-grinder



A. PELLOW.

LENS GRINDER.

APPLICATlON FILED JULY 17,1919. 1,399,400. Patented Dec. 6, 1921.

FIGJY FISE" lNvENToR ARTHUR vPELLOW BY Hf Hdtg MM ATTom'fufs UNITED STATES CIATION OF MASSACHUSETTS.

PATENT O LEN' S- GRIN DEB..

To all 'whom t may concern.'

Be it known that I, ARTHUR PELLOW, a citizen of the United States, residing at Southbridge, in the county of Worcester and State of Massachusetts, have invented certain new and useful Improvements in Lens- Grinders, of which the following is a specification.

This invention relates to improvements 1n lens grinding, and has particular reference to an improved construction of lap or tool tor use in forming the desired curve on the lens.

Prior to my invention great waste has been experienced in connection with the grinding of lenses due to the fact that the grinding tools, particularly as employed 1n grinding lenses in quantities, or 1n grinding large pieces of glass, must be initially foi-medito a certain curve, while as the grinding operation is carried out the curve will wear deeper and deeper directly down onto the tool, while there will be lateral portions which will not be subject to this wear, with the result that ordinarily only about one-third ot' the material of the tool may be used and the other two-thirds wasted. rlhis is an important item in connection with the commercial production of lenses on a large scale.

lt is, therefore, one of the objects of my present invention to provide a novel and improved construction of tool in which the parts shall be so formed and capable of such adjustment that a maximum of Wear may be attained.

in connection with the prior art grinding ot lenses it has frequently been the custom,

curve is relatively short.

A further object of my present invention, therefore, is to provide a novel and improved construction by which the tool .may be readily varied to compensate for this wear, to the end that the necessary curve may be Specication of Letters Patent.

`grinding Patented Dec. 1919. serial No. 311,405.

maintained and maximum wear of the several parts of the tool accomplished.

ther objects and advantages of my improved construction should be readily apthe following specilication taken in connection with the accompanying drawings, and it will be understood that ke any modifications in the of construction shown and described within the scope of the appended claims without departing from or exceeding the spirit of my invention.

igure l represents a side view of a grinding machine embodying my improvement.

Fig. lll represents a front view thereof.

F ig. lll represents anedge view of the wheel removed.

Fi llV represents a view similar to Fig. Hl sowing the wear of the tool.

F ig. V ing the manner sate for such wear.

Fig. Vl represents a sectional other form of construction.

Big. VH represents a view illustrating the adjustment of parts of Fig. Vl to compensate for wear.

view of anln the drawings, the numeral l designates the frame of a machine having journaled therein the horizontal shaft 2 and the ver# tical shaft 3. ounted upon the horizontal shaft is a grinding wheel or. tool 4 colens block 5 driven from to secure the grinding of the 5.

the shaft 3 by th necessary cross lenses carried by the block ig. Hl illustrates a sectional view of onel of my improved grinding tools made up of the sections A, and D, suitably secured together as by the bolts 7.

Fig. IV indicates by the dotted lines 8 the rigilnal extent of away, being useless for the production of the type of lens for which it Was intended.

ith my improvement, however, it is merely to separate the grind' removing the disks C and D, and interposing between the disks A and B the and F of increased diameter, as The disks A and B represents a similar View illustratof adjustment to compen-l ing tool if 'that in place of l from each of the disks.

equally applicable to regular concave or conindicated by now form the shorter side portions andare of the proper height Jfor this purpose so an entire new tool being formed only half a tool or central portion has been inserted.

It will be understood moreover that while I have'shown the tool as composed of but four parte, that any number of laminations or disks ma be' employed for this purpose, the idea being that in each case the dis 'starting at the center is worn down to edge size when it is removed, its place having been taken each time by a new disk so that the work need not be long delayed in forming a new tool, while maximum use is obtained vex tools. In the' case ot concave tools, for shown in Figs. VI and VII, the tool is similarly built u of a number of laminations or layers he d together by bolts 10. These lamnations after the irst construction of the tool start in as thesolid blocks or plates G, while as the grinding progresses they will gradually be worn into larger and larger rings until they reach the condition of the top ring shown at H, Fig. VI. They having then outlived their use-y Jrulness iny connection" with this particular curve, the ring H is removed and a new plate takes the place of I, which wears up gradually into the form of the plates I, J, K and L, which in succession are moved up.'h Ward as' wasthe plate H until iinally removedA as no longer useful in this particular place, although possibly useful in connection with a diierent curve, the grinding keeping thecurve constant and enabling the several disks to be thoroughly used until the larger portion has served its intended purose, the portion actually being used being the dividing lines and Narrows vided on the The same idea is the il in connection with Fig. VI, trom which it will be seen that considerably over halt' ot the plate is used up before it reaches the final position H and is removed.

In addition I would call particular attion to the 'fact of the series of plates slight grooves are proface of the lap, which it desired may be accentuated by holding the plates in slightly spaced relation. These grooves form emery receiving channels or pockets aiding in insuring the proper supply of abrasive being at all times present between the lens and surface being ground.

l. The process of constructing and maintaining a lens grinding tool in pro-per opera* tive condition consisting in detachably connecting a series of plates, forming a proper curve on the edge of a series oi such plates, and restoring the tools as worn by progressively shifting the plates outwardly from the summit, and building up the tool at the summit by the insertion of additional plates.

2. The process of constructing and reconstructing a grinding tool to secure maximum wear from the grinding tool, consisting in buildin the tool of a series of laminations separab y connecting said lamnations and progressively shifting the laminations from summit to edge of the curve being ground thereby, inserting new units at the summit, and removing a unit from the edge as a new unit is placed at the summit to preserve the wear and bulk of the tool substantially conetant. i

In testimony signature in presence of two witnesses.

ARTHUR PELLOW.

Vitnesses: y ALICE G. HASKELL,

H. E. COLEMAN.

that on account oit the use whereof I have affixed my I 

